Field of the Invention
The present invention relates to an image processing apparatus and a control method thereof.
Description of the Related Art
In recent years, a high resolution image format is being proposed. For example, in digital cinema, an image format in a number of pixels (3840×2160 pixels) that is quadruple the number of pixels of full high definition (HD: 1920×1080 pixels) is being proposed.
In order to process this kind of image having a high resolution (high resolution image), a high-speed signal processing circuit is required. Nevertheless, the device cost will increase if such a high-speed signal processing circuit is used.
Thus, considered is a method of processing a high resolution image using a low-speed signal processing circuit by dividing the high resolution image into a plurality of divided images, and performing image processing, in parallel, on the plurality of divided images by using a plurality of signal processing circuits.
Nevertheless, when spatial filter processing of referring to a neighborhood pixel is performed on the divided image, appropriate processing results cannot be obtained since the values of proper pixels (pixels of other divided images) are not referred to at the boundary portion with the other divided images. Thus, when generating a high resolution image by synthesizing the divided images that have been subj ected to image processing and subsequently displaying such high resolution image, the pixel values between the divided images become discontinuous, and there are cases where a boundary line becomes visible.
In order to resolve the foregoing problem, proposed is technology of adding, to an edge portion of a divided image, a margin image generated from a divided image (adjacent image) which is adjacent to that divided image upon dividing a high resolution image into a plurality of divided images (for example, refer to Japanese Patent Application Publication No. 2010-245961 or Japanese Patent Application Publication No. 2008-263646). By using the foregoing technology, it is possible to obtain appropriate processing results at the boundary portion between the divided images, and inhibit the generation of the boundary line described above. This kind of technology is disclosed in, for example, Japanese Patent Application Publication No. 2010-245961 and Japanese Patent Application Publication No. 2008-263646.